mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-08-31 22:18:28 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 9

[3.11] GH-99729: Unlink frames before clearing them (#100047)

Browse source
This commit is contained in:
Brandt Bucher 2022-12-06 09:02:19 -08:00 • committed by GitHub
parent 3fae04b10e
commit 2182a71eed
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
4 changed files with 56 additions and 10 deletions
Download patch file Download diff file Expand all files Collapse all files

18
Python/ceval.c
View file

@ -1617,14 +1617,6 @@ trace_function_exit(PyThreadState *tstate, _PyInterpreterFrame *frame, PyObject
return 0;
}
static _PyInterpreterFrame *
pop_frame(PyThreadState *tstate, _PyInterpreterFrame *frame)
{
_PyInterpreterFrame *prev_frame = frame->previous;
_PyEvalFrameClearAndPop(tstate, frame);
return prev_frame;
}
/* It is only between the PRECALL instruction and the following CALL,
* that this has any meaning.
*/
@ -2441,7 +2433,10 @@ handle_eval_breaker:
DTRACE_FUNCTION_EXIT();
_Py_LeaveRecursiveCallTstate(tstate);
if (!frame->is_entry) {
frame = cframe.current_frame = pop_frame(tstate, frame);
// GH-99729: We need to unlink the frame *before* clearing it:
_PyInterpreterFrame *dying = frame;
frame = cframe.current_frame = dying->previous;
_PyEvalFrameClearAndPop(tstate, dying);
_PyFrame_StackPush(frame, retval);
goto resume_frame;
}
@ -5833,7 +5828,10 @@ exit_unwind:
assert(tstate->cframe->current_frame == frame->previous);
return NULL;
}
frame = cframe.current_frame = pop_frame(tstate, frame);
// GH-99729: We need to unlink the frame *before* clearing it:
_PyInterpreterFrame *dying = frame;
frame = cframe.current_frame = dying->previous;
_PyEvalFrameClearAndPop(tstate, dying);
resume_with_error:
SET_LOCALS_FROM_FRAME();

3
Python/frame.c
View file

@ -123,6 +123,9 @@ _PyFrame_Clear(_PyInterpreterFrame *frame)
* to have cleared the enclosing generator, if any. */
assert(frame->owner != FRAME_OWNED_BY_GENERATOR ||
_PyFrame_GetGenerator(frame)->gi_frame_state == FRAME_CLEARED);
// GH-99729: Clearing this frame can expose the stack (via finalizers). It's
// crucial that this frame has been unlinked, and is no longer visible:
assert(_PyThreadState_GET()->cframe->current_frame != frame);
if (frame->frame_obj) {
PyFrameObject *f = frame->frame_obj;
frame->frame_obj = NULL;